During planning of a publication, ad sellers negotiate with ad buyers as to price, size and placement of advertisements in the publication. Negotiations can be time-consuming, slow, and laborious.
Consider advertisements for the release of a new commercial product (e.g., a car, movie). The release of a new product is typically accompanied by a national advertising campaign. Advertisements are used to ramp up public interest prior to the product release, and maintain the interest during the product's run. An advertising campaign might include placing advertisements in magazines and other printed publications. Given its slow nature, negotiations for advertisements are typically conducted long before the publications go to print.